IRS/State Interest
and Penalty Software

Project and verify IRS interest
and penalty calculations

Take the Uncertainty Out of Calculating IRS Interest and Penalties

Accurate interest and penalty calculations shouldn’t be difficult. Checking an IRS transcript. Preparing an amended return or a return for a late or non-filer. Determining penalty amounts. TaxInterest software is the professional standard that helps you calculate the correct amounts – easily, reliably, and with no guesswork.

TaxInterest System Requirements

Operating System: Windows XP or higher and Windows Server 2003 or higher
(Citrix is being used successfully with no known issues in this environment)

Memory: At least 10MB RAM

Hard Disk Space: At least 5MB free disk space

“TaxInterest is the only way to check your bills from the IRS. Manual calculations are impossible and I don’t feel comfortable with the calculations from my tax package."

— Ron S., Corporate Tax Manager, Fortune 100 Company

"I use TaxInterest proactively to show my clients position and to negotiate with the IRS.”

— Edmund N.

"Our Fin 48 solution software doesn’t do interest calculations. TaxInterest has been the perfect complement to handle that for our firm.”

— Dana D., Tax Analyst

"I had to accrue interest on a bankruptcy from an old subsidiary. Our accounting firm recommended TaxInterest and it gave us the numbers we needed. We also plan to use it for FIN 48.”

— Marla E., CPA

"TaxInterest is a great tool for doing Excise Tax refunds. We rely on it every quarter.”

— Kim F., CPA

"The IRS charged my client $20,000 in delinquent penalties. I did the calculation and saved my client $16,000. I charged a small percentage of the savings and made $1,000 an hour for that. You can use it to fight the IRS. My clients know exactly what they owe.”

— Michael F., CPA

"TaxInterest is worth every penny. It is vital for checking interest figures. TaxInterest can pay for itself in one use!”

— Joseph M., CPA

"I saved a client $3,000 on a deficiency. I made more than I paid for the software right there.”

— Peggy B., EA

IF YOU BELIEVE THAT INTEREST AND PENALTY CALCULATIONS ARE “NEVER” OVERSTATED BECAUSE TAXING AUTHORITIES DON’T MAKE MISTAKES, THEN YOU DON’T NEED TAXINTEREST.

Explore TaxInterest

The TaxInterest software interface makes your task simple. It is equally useful for doing a quick what-if calculation for an interest projection or for tying out the numbers on a state or IRS transcript.

TaxInterest Takes the Unknown Out of Calculating IRS Interest and Penalties

Enter Tax and Payment Amounts

Simple event entry makes it easy to catch errors and provide comprehensive service to your clients.

Check Penalty Notices

Double-check IRS and state interest and penalty notices in minutes or be proactive before a notice arrives.

Produce Reports to Back-up your Numbers

TaxInterest reports are widely recognized as the standard in documenting calculations.

Frequently Asked Questions

Are the state's interest calculation methods built into the program?

Many states calculate interest differently from daily compounding to annual compounding to exact days with simple interest. The calculation methodology is built in for each state.

Can I use TaxInterest for other past due tax amounts other than income taxes?

The IRS has one interest rate and some deviations from that. Most states have one interest rate for all their taxes. So the answer is probably yes. There are a few states that have different rates for different taxes. You can build custom tables in TaxInterest too.